Designation:F2722−15StandardPracticeforEvaluatingMobileBearingKneeTibialBaseplateRotationalStops1ThisstandardisissuedunderthefixeddesignationF2722;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversalaboratory-basedinvitromethodforevaluatingthemechanicalperformanceofmaterialsanddevicesbeingconsideredforreplacementofthetibio-femoraljointinhumankneejointreplacementprosthesesinmobilebearingkneesystems.1.2Mobilebearingkneesystemspermitinternalexternalrotationtotakeplaceononeorbotharticulatingsurfaces.Somedesignsplacephysicallimitsorstopstotheamountofrotation.Otherdesignsmayhaveincreasesofaresistanceforcewithincreasesinrotation.1.3Althoughthemethodologydescribesattemptstoiden-tifyphysiologicallyrelevantmotionsandforceconditions,theinterpretationofresultsislimitedtoaninvitrocomparisonbetweenmobilebearingkneedesignsandtheirabilitytomaintaintheintegrityoftherotationalstopfeatureandtibialbearingcomponentunderthestatedtestconditions.1.4Thispracticeisonlyapplicabletomobilekneetibialsystemswitharotationalstop.1.5ThevaluesstatedinSIunitsareregardedasstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2F2083SpecificationforKneeReplacementProsthesisF2003PracticeforAcceleratedAgingofUltra-HighMo-lecularWeightPolyethyleneafterGammaIrradiationinAir3.Terminology3.1Definitions:3.1.1bearingaxis—thelineconnectingthelowestpointsonboththelateralandmedialcondylesofthesuperiorsurfaceofthemobilebearing.3.1.2inferiorarticulatinginterfaces—anyinterfaceinwhichrelativemotionoccursbetweentheundersideofthemobilebearingcomponentand...